Anti-siphon trap



Sept 16, 1958 i s. J. sHAMr-:s r-:TAL 2,852,034

ANTI-SIPHON TRAP Filed March 9, 1953 nited States Patent ANTI-SIIHON TRAP Sidney J. Shames, Queens, N. Y., and Hugh J. McGuire,

Cheshire, Conn.

Application March 9, 1953, Serial No. 341,118

3 Claims. (CL 137-217) 'This invention relates to an anti-Siphon trap and more particularly to an anti-Siphon trap for use primarily in a plumbing system wherein the fluid is normally not under pressure.

Generally, anti-Siphon traps, or vacuum breakers as they are also referred to, have been used to prevent back siphonage from water closets to which water is delivered under pressure directly from the water supply. Such devices are usually bulky and unsightly but are necessary 'to prevent contamination of the water supply, which would occur if back siphonage took place.

In the drainage of water bowls and sinks there is no direct connection between the pressurized water supply and the drain pipe, and, while the problem of contamination of water supply by back siphonage does not exist, it is, nevertheless, desirable to completely eliminate the possibility of emptying the sink trap by siphoning. If a sink trap is permitted to become emptied by siphoning, quite often sewer gas backs up through the drain pipe and into the room where the sink is located. This sewer gas is poisonous and has a very nauseating odor, and, thus, entrance of sewer gas into the home is very undesirable. However, very little has been done to eliminate this problem because there has been no really inexpensive or simple way of eliminating this problem, and the use of a water closet type vacuum breaker is unsightly, clumsy and uneconomical.

Thus, it is the object of this invention to provide a very simple, neat, and economical anti-Siphon trap for a non-pressurized plumbing system.

Another object of this invention is to provide an antisiphon trap for sinks which may be incorporated into the pipe fitting connection between the sink trap and the sink drain pipe.

A further object of this invention is to provide an anti-Siphon valve which attains the objects set forth and which further prevents water leakage therethrough if the water should back up, as may occur when the sink trap is blocked.

Further objects and advantages of this invention will become apparent as the following description proceeds and the features of novelty which characterize this invention will be pointed out with particularity in the claims annexed to and forming part of this specification.

A preferred embodiment of the invention is shown in the accompanying drawing, in which:

Figure l is an elevation view of a sink provided with a sipnon trap, illustrating the general location of the antisiphon valve of this invention.

Figure 2 is an enlarged elevation view, partly in crosssection of the sink trap and anti-siphon valve.

Figure 3 is a plan view, with parts broken away, taken subtantially on line 3 3 of Figure 2.

Figure 4 is a greatly enlarged viewof the portion of the anti-Siphon valve encircled in Figure 2, showing the seal ring in its lowermost position.

Figure 5 is similar to Figure 4 and shows the seal ring in its uppermost position.

Referring now to the drawings there is shown in Figure l a sink having a goosenecked drain generally indicated at 12 extending therebelow. The drain 12 includes ice a discharge tube 14, a second tube 16, and a third tube segment 18 to which the second tube segment 16 is connected by means of a tting 2t). The tting 20 is prefer ably a compression type fitting or the equivalent which prevents iiuid leakage therethrough. The second tube 16 is U-shaped at 22 to form a trap which prevents the backing-up of noxious odors from the sewer into the room wherein the sink 10 is positioned. The improvement in the drainage system generally shown in Figure l and described above, is clearly shown in Figures 2 to 4. This improvement comprises incorporating a vacuumbreaker or anti-Siphon valve in the iluid line above the sink trap.

Referring now to Figures 2 to 4, there is shown the drain pipe or discharge tube 14 which extends vertically downwardly. The lower end 24 of the discharge tube, 14 extends concentrically within a portion of the second tube 16. The concentric portions of tubes 14 and 16 define an annular passageway 26 therebetween. The Ufshaped portion 22 of second tube 16 is shown filled with water, which is the usual case when the trap is functioning properly.

Sealingly secured to the upper end of the second tube 16, in any appropriate manner such as by welding or by a sweat fit, is an annular member 2S, through which the discharge tube 14 slidably extends. Said annular mem` ber 28 has a transverse portion 30 which substantially blocks the upper end of annular passageway 26.

An annular cap 32 is threaded to the annular member 2S. The annular cap 32 provides a transverse portion 34 spaced from the transverse portion 30 of the annuiar member 28. The transverse portions 30 and 34 and the wall of discharge tube 14 bound or define an annular chamber 36 which surrounds the discharge tube 14.

The transverse portion 30 of annular member 28 is provided with a plurality of circularly disposed air vents Si; bored therethrough and serving to communicate the annular passageway 26 with chamber 36. The transverse portion 34 of cap 32 has circularly disposed air vents 4t) bored therethrough serving to communicate chamber 36 with the atmosphere.

A distortable seal 42 is provided in annular chamber 36, and said seal fits snugly on tube 14. Said seal 42 is clamped between cap 32 and annular member 28 to provide sealing means which blocks seepage of water through the passage 44 between tube 14 and annular member 28. T he vents 38 and 4d are so arranged and seal/42 is of such a size that in the assembly condition, as seen in Figures 4l and 5, seal 42 is disposed radially inwardly of vents 3S and 40 and does not block said vents.

in the anti-Siphon valve, there is also provided an annular seal ring 46 of a buoyant material positioned inannular passageway 26. Suicient clearance is provided between seal ring 46 and the walls of discharge tube 14 and of second tube 16 to prevent jamming of the buoyant ring against the wall's of said tubes, and also to provide venting passages around said ring 46. The buoyant seal ring 46 is adapted to move into and out of engagement with the transverse portion Sti of annular member 28 to respectively seal or open the vent openings 3S.

A crimp or llange 48 is provided in tube 16 and extends into annular passageway 26. This crimp 48 is spaced from the wall of drainage tube 14 andis also spaced below the transverse portion 36 of annular member 218. The crimp48 is adapted to limit the downward movement of the seal ring 46 within the annular passageway 26. Accordingly, the range of movement of the buoyant seal ring 46 is from adjacent crimp 48, as `shown in Figure 4, to adjacent the transverse portion 30 of annular member 2S, as shown in Figure 5.

senese As clearly seen in Figures 4 and 5, the axes of vents 33 and 40 are misalifrned to provide an obstruction to prevent spitting of the anti-Siphon valve which might occur it' some water happens to get past seal ring 46 'and into vents 33. As further seen in Figure 3, the vents 38 and d0 may be further misaligned by relative rotation of cap 32 with respect to annular member 28, thus providing a further obstruction to prevent spitting of the antisiphon valve.

In operation, the seal ring 46 is normally in the position shown in Figures 2 and 4 with the air vents i0 and 38 providing venting to the interior of tube 16 so as to provide an anti-Siphon or vacuum-breaking means. lf the water in tube 16 should back up because of clogging thereof, or due to some other reason, the buoyant seal ring 46 is moved upward by the Water to the position shown in Figure 5 and blocks olf vents 3S, thus preventing water leakage through the anti-Siphon or vacuumbreaking means.

What has been provided, as this description discloses,

is a very simple and novel vacuum-breaker or anti-Siphon means which is incorporated in elements which are normally provided in ordinary drainage systems, and which anti-Siphon means are not bulky or unsightly, and which anti-Siphon means now provides a safety feature where previously none had existed.

While there has been shown and described a particular embodiment of this invention, it will be obvious to those skilled in the art that various changes and modifications may be made therein without departing from the invention, and, therefore, it is intended in the appended claims to cover all such changes and modiiications as fall within the true spirit and scope of the invention.

What we claim as new and desire to secure by Letters Patent of the United States is:

1. In a vacuum breaker for use in a non-pressurized liquid system including a vertically extending discharge tube, and a second tube of larger diameter than said discharge tube positioned concentric with said discharge tube and extending therebelow and adapted to receive the llow from said discharge tube, said concentric tubes defining a substantially vertically extending annular passageway therebetween; said vacuum breaker comprising an annular member sealingly secured to the upper end of said second tube and having said discharge tube slidably extending tion thereof spaced from said transverse portion of said annular member to define an annular chamber surrounding said discharge tube, a plurality of vent openings in said transverse portion of the annular member communicating the annular passageway to said annular chamber, a plurality of vent openings in said transverse portion of the annular cap communicating said annular chamber to the atmosphere, an annular buoyant seal ring movably positioned in said annular passageway, said buoyant seal ring adapted to move into and out of engagement with said transverse portion of the annular member to respectively seal or open the vent openings therethrough, means within said annular passageway for limiting downward movement of said buoyant seal ring, and means in said annular chamber for blocking passage of liquid between said annular member and said discharge tube.

2. In a vacuum breaker for use in a non-pressurized liquid system including a vertically extending discharge tube, and a second tube of larger diameter than said discharge tube positioned concentric with said discharge tube and extending therebelow and adapted to receive the flow from said discharge tube, said concentric tubes deining a substantially vertically extending annular passageway therebetween; said vacuurn breaker comprising an annular member sealingly secured to the upper end of Cit said second tube and having said discharge tube slidably extending therethrough, said annular member including a transverse portion which substantially blocks the upper end of said annular passageway, an annular cap threaded to said annular member and having a transverse portion thereof spaced from said transverse portion of said annular member to define an annular chamber surrounding said discharge tube, a plurality of vent openings in said transverse portion of the annular' member communicating the annular passageway to said annular chamber, a plurality of vent openings in said transverse portion of the annular cap communicating said annular passageway to the atmosphere, an annular buoyant seal ring movably positioned in said annular passageway, said buoyant seal ring adapted to move into and out of engagement with said transverse portion of the annular member to respectively seal or open the vent openings therethrough, means Within said annular passageway for limiting downward movement of said buoyant seal ring, and a distortable seal in said annular chamber clamped between said transverse portions of the annular member and the annular cap, for blocking the passage of fluid between said annular member and said discharge tube, said distortable seal being located radially inwardly of said vent openings in the annular member and annular cap.

3. In a vacuum breaker for use in a non-pressurized liquid system including a vertically extending discharge tube, and a second tube of larger diameter than said discharge tube positioned concentric with said discharge tube and extending therebelow and adapted to receive the ow from said discharge tube, said concentric tubes detining a substantially vertically extending annular passageway therebetween; said vacuum breaker comprising an annular member sealingly secured to the upper end of said second tube and having said discharge tube slidably extending therethrough, said annular member including a transverse portion which substantially blocks the upper end of said annular passageway, an annular cap threaded to said annular member and having a transverse portion thereof spaced from said transverse portion of the annular member to define an annular chamber surrounding said discharge tube, a plurality of vent openings in said transverse portion of the annular member communicating the annular passageway to said annular chamber, a plurality of vent openings in said transverse portion of said annular cap communicating said annular chamber to the atmosphere, an annular buoyant seal ring movably positioned in said annular passageway, said buoyant seal ring adapted to move into and out of engagement with said transverse portion of the annular member to respectively seal or open the vent openings therethrough, the vent openings in the annular member and the vent openings in the annular cap being misaligned, a distortable seal in said annular chamber clamped between said transverse portions of the annular member and the annular cap for blocking passage of liquid between said annular member and said discharge tube, said seal being located radially inwardly of the vent openings in said annular member and annular cap, and a iiange on the inner periphery of said second tube extending into said annular passageway and spaced from said discharge tube for limiting the downward movement of said buoyant seal ring.

References Cited in the le of this patent UNITED STATES PATENTS 1,059,609 Hollis Apr. 22, 1913 2,023,788 Miller Dec. 10, 1935 2,028,581 Zinkil Ian. 21, 1936 2,096,844 Cekal Oct. 26, 1937 2,216,808 Delaney Oct. 8, 1940 2,217,027 Obrien Oct. 8, 1940 2,217,132 Obrien Oct. 8, 1940 2,303,044 Goodrie Nov. 24, 1942 2,310,586 Lohman Feb. 9, 1943 

